The present invention relates to an image signal processing apparatus. For example, the present invention relates to an image signal processing apparatus that conducts noise correction and various image corrections which change a signal level.
As a background field of the present technique, there is, for example, JP-B-4109001 (Patent Literature 1). A technique disclosed in JP-B-4109001 has an object represented as “the present invention provides a new picture quality correction method that improves picture quality correction by conducting favorable noise removal on an image when conducting prescribed picture quality correction such as contrast correction and brightness correction.” The technique disclosed in JP-B-4109001 is “configured to include (1) a process for calculating a correction quantity of picture quality correction on a level value of an image on the basis of the level value, (2) a process for determining a removal f noise on the basis of a correction quantity in a region of an image to which noise removal processing is applied or its nearby region, (3) a process for removing noise by taking a region of the image as a unit and in accordance with the determined noise removal intensity, and (4) a process for conducting picture quality correction on the image with noise removed, when conducting the prescribed picture quality correction on an image.”